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1) Field of the Invention
The use of ramps by vehicles and others to bridge obstacles is well known. Their shape, size, weight and portability is usually of little concern in the industrial environment. This is not true, however, to the handicapped or elderly user, since their ability to handle such conditions is severely limited. The ability to personally carry, deploy and return to storage, is a major factor in their independence.
Much of the prior art gives only partial consideration to the above concerns. In the past, when attention is given to ease of storage, we find it necessary to store several components separately, thereby increasing the risk of losing some of the components. When consideration is given to unitized construction, we are left with a large, heavy and cumbersome ramp that is difficult to store.
The prior art cited below exhibit these limiting factors. We will show that by attention to detail, a ramp overcoming these limitations can be inexpensively produced.
The present invention relates to collapsible, portable ramps of a unitary construction that are particularly suitable for use by, but not limited to, wheelchairs and other vehicles commonly used by the disabled, elderly or other persons requiring transportation assistance.
2) Description of Related Art
Everard et al. U.S. Pat. No. 5,347,672 disclosed a xe2x80x9cportable, stowable knock-down rampxe2x80x9d in which one or more separate side rails must be attached to a central platform made from a series of interlocking metal extrusions. While providing the basic function of bridging a curb or a series of steps, the Everard et al. ramp construction is cumbersome to use due to the size and weight of key components, and due to the fact that ramp plates must be precisely inserted and locked into the side rail for proper and safe use. Also, the fact that the side rails are carried separately, increases their risk of loss and damage during storage.
Estes et al. U.S. Pat. No. 5,933,898 discloses a xe2x80x9cportable wheelchair rampxe2x80x9d which provides a knock-down ramp in which a series of interconnected spanning panels are deployed and locked together to form the basic function of bridging a curb or a series of steps. The Estes et al. ramp construction is cumbersome to use due to the size and weight of key components and due to the fact that the spanning panels must be locked together for proper and safe use.
The present invention provides a collapsible, portable ramp assembly, made of light weight materials and of a unitized construction whereby all components are a permanent part of the assembly, and which can be quickly and easily deployed to form a sturdy ramp for a variety of uses. Due to its unique construction, the portable ramp may be easily broken down without the need for component removal. It may also be rolled up into a single, small, compact package for carrying in a tote-bag.
In the preferred embodiment, the central, load-bearing portion of the ramp is formed by many light weight, transversely positioned slats, pivotally connected to one another by several flexible straps. Rigid support of the central ramp portion is provided by a pair of strong, light weight braces that simply rotate into a longitudinal position along the ramp sides from their position along the ramp end pieces. When no longer in use, the braces are rotated back and locked into their transverse position along the end pieces of the ramp for easy storage. Since the braces need not be removed or re-attached to the central ramp portion of the assembly, the ramp is easily roll up into a single package for storage in a tote-bag suitable for hanging on the back of a wheelchair, or similar vehicle.